ID   STXA_BP788              Reviewed;         315 AA.
AC   Q779K4; Q7B2T8;
DT   04-DEC-2007, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   29-SEP-2021, entry version 61.
DE   RecName: Full=Shiga toxin subunit A;
DE            EC=3.2.2.22;
DE   Flags: Precursor;
GN   Name=stxA;
OS   Shigella phage 7888 (Shigella sonnei bacteriophage 7888).
OC   Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC   Caudovirales; Podoviridae; Sepvirinae; Traversvirus;
OC   unclassified Traversvirus.
OX   NCBI_TaxID=138946;
OH   NCBI_TaxID=624; Shigella sonnei.
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=10232325; DOI=10.1016/s0140-6736(99)00961-7;
RA   Beutin L., Strauch E., Fischer I.;
RT   "Isolation of Shigella sonnei lysogenic for a bacteriophage encoding gene
RT   for production of Shiga toxin.";
RL   Lancet 353:1498-1498(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=11705937; DOI=10.1128/iai.69.12.7588-7595.2001;
RA   Strauch E., Lurz R., Beutin L.;
RT   "Characterization of a Shiga toxin-encoding temperate bacteriophage of
RT   Shigella sonnei.";
RL   Infect. Immun. 69:7588-7595(2001).
CC   -!- FUNCTION: The A subunit is responsible for inhibiting protein synthesis
CC       through the catalytic inactivation of 60S ribosomal subunits. After
CC       endocytosis, the A subunit is cleaved by furin in two fragments, A1 and
CC       A2: A1 is the catalytically active fragment, and A2 is essential for
CC       holotoxin assembly with the B subunits (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Endohydrolysis of the N-glycosidic bond at one specific
CC         adenosine on the 28S rRNA.; EC=3.2.2.22;
CC   -!- SUBUNIT: Shiga toxin contains a single subunit A and five copies of
CC       subunit B. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the ribosome-inactivating protein family.
CC       {ECO:0000305}.
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DR   EMBL; AJ132761; CAA10763.1; -; Genomic_DNA.
DR   EMBL; AJ279086; CAC12887.1; -; Genomic_DNA.
DR   SMR; Q779K4; -.
DR   GO; GO:0030598; F:rRNA N-glycosylase activity; IEA:UniProtKB-EC.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0098676; P:modulation of host virulence by virus; IEA:UniProtKB-KW.
DR   GO; GO:0017148; P:negative regulation of translation; IEA:UniProtKB-KW.
DR   Gene3D; 3.40.420.10; -; 1.
DR   Gene3D; 4.10.470.10; -; 1.
DR   InterPro; IPR036041; Ribosome-inact_prot_sf.
DR   InterPro; IPR001574; Ribosome_inactivat_prot.
DR   InterPro; IPR017988; Ribosome_inactivat_prot_CS.
DR   InterPro; IPR016138; Ribosome_inactivat_prot_sub1.
DR   InterPro; IPR016139; Ribosome_inactivat_prot_sub2.
DR   InterPro; IPR016331; Shiga-like_toxin_subunit_A.
DR   Pfam; PF00161; RIP; 1.
DR   PIRSF; PIRSF001924; Shigella_toxin_subunit_A; 1.
DR   SUPFAM; SSF56371; SSF56371; 1.
DR   PROSITE; PS00275; SHIGA_RICIN; 1.
PE   3: Inferred from homology;
KW   Disulfide bond; Hydrolase; Modulation of host virulence by virus;
KW   Protein synthesis inhibitor; Signal; Toxin; Viral exotoxin; Virulence.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000255"
FT   CHAIN           23..315
FT                   /note="Shiga toxin subunit A"
FT                   /id="PRO_0000312304"
FT   REGION          23..273
FT                   /note="A1"
FT   REGION          274..315
FT                   /note="A2"
FT   ACT_SITE        189
FT                   /evidence="ECO:0000250"
FT   SITE            273..274
FT                   /note="Cleavage; by furin"
FT                   /evidence="ECO:0000250"
FT   DISULFID        264..283
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   315 AA;  34814 MW;  8A423DF7ABF58F30 CRC64;
     MKIIIFRVLT FFFVIFSVNV VAKEFTLDFS TAKTYVDSLN VIRSAIGTPL QTISSGGTSL
     LMIDSGTGDN LFAVDVRGID PEEGRFNNLR LIVERNNLYV TGFVNRTNNV FYRFADFSHV
     TFPGTTAVTL SGDSSYTTLQ RVAGISRTGM QINRHSLTTS YLDLMSHSGT SLTQSVARAM
     LRFVTVTAEA LRFRQIQRGF RTTLDDLSGR SYVMTAEDVD LTLNWGRLSS VLPDYHGQDS
     VRVGRISFGS INAILGSVAL ILNCHHHASR VARMASDEFP SMCPADGRVR GITHNKILWD
     SSTLGAILMR RTISS